/// <summary>
/// Initializes a new instance of the <see cref="randstate_t"/> class.
/// </summary>
/// <param name="algorithm">The algorithm.</param>
/// <param name="parameters">The algorithm parameters.</param>
private randstate_t(RngAlgorithm algorithm, object[] parameters)
{
switch (algorithm)
{
default:
case RngAlgorithm.Default:
mp_randinit_default(ref Value);
break;
case RngAlgorithm.MersenneTwister:
mp_randinit_mt(ref Value);
break;
case RngAlgorithm.LinearCongruential:
if (parameters.Length == 3 && parameters[0] is mpz_t a && parameters[1] is ulong c && parameters[2] is ulong m2exp)
{
mp_randinit_lc_2exp(ref Value, ref a.Value, (mpir_ui)c, (mp_bitcnt_t)m2exp);
}
else if (parameters.Length == 1 && parameters[0] is ulong size)
{
mp_randinit_lc_2exp_size(ref Value, (mp_bitcnt_t)size);
}
else
{
throw new ArgumentException();
}
break;
}
/// <summary>
/// Initializes a new KdbxWriter with the given options.
/// </summary>
/// <param name="cipher">The algorithm to use for encrypting the database.</param>
/// <param name="rngAlgorithm">The random number generator used for String protection.</param>
/// <param name="compression">The document compression algorithm.</param>
/// <param name="kdfParams">Recipe for transforming the raw key. This will be reseeded.</param>
private KdbxWriter(
EncryptionAlgorithm cipher,
RngAlgorithm rngAlgorithm,
CompressionAlgorithm compression,
KdfParameters kdfParams
)
: base()
{
SeedHeaderData(cipher, rngAlgorithm, compression, kdfParams);
}
/// <summary>
/// Initializes a new KdbxWriter with the given options.
/// </summary>
/// <param name="tokenList">An enumeration of security tokens used for encryption.</param>
/// <param name="cipher">The algorithm to use for encrypting the database.</param>
/// <param name="rngAlgorithm">The random number generator used for String protection.</param>
/// <param name="compression">The document compression algorithm.</param>
/// <param name="kdfParams">Recipe for transforming the raw key.</param>
public KdbxWriter(
IEnumerable <ISecurityToken> securityTokens,
EncryptionAlgorithm cipher,
RngAlgorithm rngAlgorithm,
CompressionAlgorithm compression,
KdfParameters kdfParams
)
: this(cipher, rngAlgorithm, compression, kdfParams)
{
this.securityTokens = securityTokens ?? throw new ArgumentNullException(nameof(securityTokens));
}
/// <summary>
/// Ensures the writer's serialization settings are correct for the given user preferences.
/// </summary>
/// <param name="cipher">The algorithm to use for encrypting the database.</param>
/// <param name="rngAlgorithm">The random number generator used for String protection.</param>
/// <param name="compression">The document compression algorithm.</param>
/// <param name="kdfParams">Recipe for transforming the raw key. This will be reseeded.</param>
private void SeedHeaderData(
EncryptionAlgorithm cipher,
RngAlgorithm rngAlgorithm,
CompressionAlgorithm compression,
KdfParameters kdfParams
)
{
if (kdfParams == null)
{
throw new ArgumentNullException(nameof(kdfParams));
}
KdbxVersion version = KdbxVersion.Three;
if (cipher == EncryptionAlgorithm.ChaCha20 || rngAlgorithm == RngAlgorithm.ChaCha20 ||
!kdfParams.Uuid.Equals(AesParameters.AesUuid))
{
DebugHelper.Trace("Using KDBX4 for serialization due to header parameters");
version = KdbxVersion.Four;
}
this.parameters = new KdbxSerializationParameters(version)
{
Compression = compression
};
// "Stream start bytes" are random data encrypted at the beginning
// of the KDBX data block. They have been superceded by HMAC authentication.
IBuffer streamStartBytes;
if (this.parameters.UseHmacBlocks)
{
streamStartBytes = new byte[0].AsBuffer();
}
else
{
streamStartBytes = CryptographicBuffer.GenerateRandom(32);
}
HeaderData = new KdbxHeaderData(KdbxHeaderData.Mode.Write)
{
Cipher = cipher, // This will automatically set EncryptionIV
Compression = compression,
MasterSeed = CryptographicBuffer.GenerateRandom(32),
KdfParameters = kdfParams.Reseed(),
StreamStartBytes = streamStartBytes,
InnerRandomStreamKey = CryptographicBuffer.GenerateRandom(32).ToArray(),
InnerRandomStream = rngAlgorithm
};
}
/// <summary>
/// Initializes a new KdbxWriter with the given options.
/// </summary>
/// <param name="rawKey">The raw 32-byte key for encryption.</param>
/// <param name="cipher">The algorithm to use for encrypting the database.</param>
/// <param name="rngAlgorithm">The random number generator used for String protection.</param>
/// <param name="compression">The document compression algorithm.</param>
/// <param name="kdfParams">Recipe for transforming <paramref name="rawKey"/>.</param>
public KdbxWriter(
IBuffer rawKey,
EncryptionAlgorithm cipher,
RngAlgorithm rngAlgorithm,
CompressionAlgorithm compression,
KdfParameters kdfParams
)
: this(cipher, rngAlgorithm, compression, kdfParams)
{
if (rawKey == null)
{
throw new ArgumentNullException(nameof(rawKey));
}
if (rawKey.Length != 32)
{
throw new ArgumentException("Raw key must be 32 bytes", nameof(rawKey));
}
this.rawKey = rawKey;
}
/// <summary>
/// Creates a random state.
/// </summary>
/// <param name="algorithm">The algorithm.</param>
/// <param name="parameters">The algorithm parameters.</param>
public static randstate_t Create(RngAlgorithm algorithm = RngAlgorithm.Default, params object[] parameters)
{
return(new randstate_t(algorithm, parameters));
}
